Natural stones such as granite and marble can have beautiful patterns on the surface thereof and thus have been used as building decoration material. Recently, the demand for natural stones for use in applications such as flooring, wall panels, sinks, and the like has significantly increased. However, this demand may not be met only with high cost natural stones. Accordingly, various artificial stones are also being developed and used.
The artificial stones are classified into general artificial stones manufactured by adding various materials such as an inorganic filler, a colorant, a curing agent, and the like to an acryl-based or unsaturated polyester base resin and resin-based engineered stones (so called “engineering stones”) manufactured by mixing an inorganic (silica-based) natural mineral and a binder resin to obtain a composition and then, vacuuming, vibrating, compressing, and molding the composition to have a texture of the natural stones.
The resin-based engineered stones may be manufactured to have various colors and textures depending on the kind of natural mineral, color of a resin or pigment, stirring process, and the like. Resin-based engineered stones may have more natural textures than the general artificial stones due to a use of the natural mineral as a main material and thus have recently been in increasing demand.
These resin-base engineered stones may be manufactured to have a single color, a multicolor tone by adding pigments having different colors from one another and mixing resin mixtures having various colors in a mixer, or a natural stone texture by using a chip.
To improve function and performance of an artificial marble, there have been attempts to impart luminance to the artificial marble by using a noctilucenct material such as a phosphorescent material and the like, a light emitting material such as an ultraviolet (UV) emitting material as well as ultraviolet (UV) absorbing material, and the like.
A conventional phosphorescent artificial marble may be manufactured by coating a phosphorescent pigment on the surface or creating a texture by using a phosphorescent chip. When the phosphorescent chip is used, uniform phosphorescence may not be obtained, and when the phosphorescent pigment is coated on the surface, the texture on the surface may be different from that of natural marble.
In addition, conventional phosphorescent artificial marble can include a large amount of the phosphorescent pigment to accomplish sufficient phosphorescence performance. However, the phosphorescent pigment is expensive and thus may increase manufacturing cost when used in a large amount and resultantly, can be an obstacle to commercial availability of the artificial marble. Accordingly, there is a need to provide sufficient phosphorescence with smaller amounts of the phosphorescent pigment.
The present inventors have researched an appropriate mixing ratio in order to solve this problem and resultantly developed a resin-based engineered stone capable of accomplishing phosphorescence which can maintain sufficient luminance for a long time as well as use a minimum amount of the phosphorescent pigment.